Method and system for multi-streaming multimedia data

ABSTRACT

A method for multi-streaming multimedia content data over a network to affiliated client devices is provided. A manifest including a list of Universal Resource Indicators (URIs) for different segments of multimedia content data for selected primary multimedia content and a list of URIs for different segments of multimedia content data for at least one alternate multimedia content related to and different from the selected primary multimedia content is built and made available for download over the network with a transfer protocol. Synchronization of display of the selected primary multimedia content on a primary display and display of the at least one alternate content on the at least one auxiliary client device is thereby enabled. A system for streaming multimedia data over a network to affiliated client devices is also disclosed.

BACKGROUND

Streaming is a technique of delivering data corresponding to mediacontent to end-users and typically involves continuously playing mediacontent as the media data is being streamed or delivered to the enduser. The streamed content can correspond to video and/or audio, and anend user may watch the streamed content, for instance, on a televisionmonitor connected to an IP client set-top box as well as other clientdevices such as tablets, smart-phones, personal and lap-top computers,and like electronic devices having or connected to display screensand/or audio speakers.

Hypertext Transfer Protocol (HTTP) Live Streaming (HLS), DynamicAdaptive Streaming over HTTP (MPEG DASH), Smooth Streaming (SS), andHTTP-based Dynamic Streaming (HDS) provide examples of techniques forstreaming content using HTTP. Incoming media data from a source issegmented or “chunked” into multiple separate media files which arestored on a server. A playlist file or manifest is created that includesUniform Resource Identifiers (URIs) that direct client devices to theaddress or location of the media segments or files on the server. Whenthe segmented media files are downloaded by a client device, the mediafiles can be reassembled and played one-by-one by the client device inaccordance with order specified in the playlist or manifest file. Thus,the user of the client device can be provided with continuous anduninterrupted playing of the media content while the client devicecontinues to download and reassemble additional chunks or segments ofthe stream.

Adaptive streaming involves producing several instances of the samesource media file and making the files containing identical contentavailable to various different types of client devices depending upontheir delivery bandwidth, CPU processing power, or the like. Forinstance, by monitoring CPU utilization and/or buffer status, adaptivestreaming technologies can change streams when necessary to ensurecontinuous playback and to otherwise improve the viewing experience.Thus, HTTP-based adaptive streaming technologies use a combination ofencoded media files and manifest or playlist files that identifyalternative streams of identical content and their respective URLs.Client devices monitor buffer status and/or CPU utilization and changestreams as necessary by locating an alternate stream of the same contentfrom the URLs specified in the manifest or playlist file.

BRIEF DESCRIPTION OF THE DRAWINGS

Various features of the embodiments described in the following detaileddescription can be more fully appreciated when considered with referenceto the accompanying figures, wherein the same numbers refer to the sameelements.

FIG. 1 is a diagram of a possible arrangement of primary and auxiliaryclient devices on a home or local area network to which content may bestreamed from a service provider in accordance with an embodiment.

FIG. 2 is an example of a structure of a Media Presentation Description(MPD) manifest file that lists a collection of audio and video contentand that incorporates periods, adaptation sets, representations andsegments in accordance with an embodiment.

FIG. 3 is a diagram of a system for multi-streaming related primary andalternate contents over a network to affiliated client devices inaccordance with an embodiment.

DETAILED DESCRIPTION

For simplicity and illustrative purposes, the principles of theembodiments are described by referring mainly to examples thereof. Inthe following description, numerous specific details are set forth inorder to provide a thorough understanding of the embodiments. It will beapparent however, to one of ordinary skill in the art, that theembodiments may be practiced without limitation to these specificdetails. In some instances, well known methods and structures have notbeen described in detail so as not to unnecessarily obscure theembodiments.

According to embodiments disclosed herein, methods and systems formulti-streaming multimedia content data over a network to affiliatedclient devices are provided.

According to one such embodiment, a method of streaming multimedia dataover a network comprises a step of building a manifest including a listof Universal Resource Indicators (URIs) for different segments ofmultimedia data for selected primary multimedia content and a list ofURIs for different segments of multimedia data for at least onealternate multimedia content related to and different from the selectedprimary multimedia content and a step of making the manifest availablefor download by a primary client device over the network with a transferprotocol.

According to another aspect of this embodiment, a method of streamingmultimedia data over a network to affiliated client devices comprises astep of downloading a manifest with a primary client device over thenetwork with a transfer protocol, the manifest including a list ofUniversal Resource Indicators (URIs) for different segments ofmultimedia data for a selected primary multimedia content and a list ofURIs for different segments of multimedia data for at least onealternate content related to the selected primary multimedia content,and a step of downloading the manifest with at least one auxiliaryclient device affiliated with the primary client device over the networkwith a transfer protocol to enable synchronization of display of theselected primary multimedia content on a primary display controlled bythe primary client device and display of the at least one alternatecontent on the at least one auxiliary client device.

According to a further aspect of this embodiment, a system for streamingmultimedia data over a network to affiliated client devices includes amulti-stream playlist rebuilder and an alternate content coordinationmanager. The multi-stream playlist rebuilder is configured to receive amanifest including a list of Universal Resource Indicators (URIs) fordifferent segments of multimedia data for a selected primary multimediapresentation, and the alternate content coordination manager isconfigured to provide the multi-stream playlist rebuilder with a list ofURIs for different segments of multimedia data for at least onealternate multimedia content that is related to and different from theselected primary multimedia presentation. The multi-stream playlistrebuilder is also configured to generate a modified manifest includingthe list of URIs for the different segments of the multimedia data forthe selected primary multimedia presentation and a list of URIs for thedifferent segments of the multimedia data for the at least one alternatemultimedia content.

Accordingly, methods and apparatus are provided for deliveringsynchronized content to multiple client devices in a coordinated manner(i.e. multi-streaming of primary and alternate contents to differentclient devices for playing and viewing simultaneously on the multipleclient devices). For example, the synchronized content may includeprimary media content for display on a primary display screen andrelated alternate media content or contents for display on affiliatedsecondary or auxiliary display screens. The ability of a singlesubscriber to consume primary and alternate contents in a coordinatedmanner at the subscriber site is enabled via the use of various types ofclient devices that can process web content, multimedia content, videoand data, and like content via streaming techniques. Accordingly,multimedia content delivery is accomplished to a multitude of clientdevices, including different types of client devices having differentcapabilities, and can be provided in the form of a suite of relatedcontent.

As one example of a streaming protocol, MPEG-DASH may be used to delivermultimedia content using an XML based playlist that has been modified orrebuilt to provide access to a multitude of time-synchronized multimediastreams accessible by client devices using HTTP. According to anembodiment, MPEG-DASH is utilized in a manner by which alternatecontents are delivered to disparate client devices. In this manner,multi-streaming of alternate content effectively forms a Meta layerabove dynamic adaptive streaming. While MPEG-DASH has been designed foradapting a single source of content to a multitude of client devices, amulti-streaming embodiment disclosed herein adapts multiple sources ofcontent for delivery to client devices and can be used to providespecific complementary content to targeted receiving client devices.

Multi-streaming can be provided by manipulating adaptive bit-rate streamplaylists (e.g., the manifest defined by HLS and MPEG-DASH) incombination with distributing alternate content to multiple auxiliary IPclient devices thereby providing a coordinated and synchronizedmulti-streaming arrangement. For instance, multi-streaming may be usedto deliver targeted advertisement content, complementary video contentsuch as alternate viewing angles, alternate multimedia content such astext, web content, slide shows or mini-video segments that mightcomplement the primary content, and many other types of content.

FIG. 1 shows an arrangement for displaying synchronized content to anend user, such as a subscriber of a service. The arrangement in FIG. 1is merely provided for purposes of example and various otherarrangements using other communication devices and protocols may beused. In FIG. 1, synchronized media content is available from a headend10 of a network 12, such as a hybrid fiber optic-coaxial cable network(HFC), to customer premise equipment (CPE) at a subscriber site. In thisexample, the subscriber has a home or local area network 14 to which anIP client set-top box 16 and wireless router 18 are connected. Theset-top box 16 is connected to a television 20, and the router 18communicates with multiple other client devices via wirelesscommunications on the home network 14, such as a tablet client device 22and a smartphone client device 24. Of course, any type of client devicecan be utilized via the home network 14 in this example, such ascomputers, personal computers, laptop computers, e-book reader, gamepads, remote controllers, and like client devices, and the network isnot limited to a cable network and can be any content distributionnetwork (CDN).

It will be understood by a person having ordinary skill in the art thatthe conventional term “set-top box” should not be construed to limit thephysical placement or configuration of such a device; for example, theset-top box 16 in FIG. 1 is neither limited to a device that is enclosedin a box, nor is it limited to a device positioned on top of atelevision set.

Media content which may be considered primary content may be consumed bythe end user via the primary video viewing device, such as provided bythe relatively large-screen television 20 in FIG. 1. At the same time,related alternate media content may also be consumed by the end user ina synchronized manner with the primary media content via use of any of afamily of affiliated auxiliary client devices, such as tablet 22 andsmartphone 24 shown in FIG. 1. There is no limit to the types of mediacontent, the number of alternate media contents, or the types or numberof auxiliary client devices affiliated with a subscriber. As one simpleexample, a baseball game may be shown on the primary video viewingdevice while video from alternate view points, related replays,statistics, score board, rules of the game, or supplementary informationare simultaneously displayed on affiliated auxiliary client devices.

As a means for providing the related synchronized media content to theend user, a HTTP-based adaptive streaming technique is utilized. Asdiscussed above, such techniques essentially include two components: thesegmented and encoded audio/video (A/V) streams; and the playlist ormanifest files that identify the streams for the client devices andcontain their addresses. The related synchronized media content can beprovided to an end user by manipulating and modifying or rebuilding theplaylist or manifest file corresponding to the primary content such thatit also includes the alternate video contents targeted to auxiliaryclient devices.

The auxiliary client device, such as tablet 22 and smartphone 24 in FIG.1, download, obtain, or fetch the same manifest or playlist file that isalso being used by the primary video viewing device (set-top box 16 andtelevision 20 in FIG. 1). For this purpose, the auxiliary client devicesare first provided with information concerning markers, keys, triggersor filters that permit the auxiliary client devices to process only apart of the manifest or playlist that is intended or applicable to thatparticular device (e.g., web data or multimedia content produced fortablet consumption, or for smartphone consumption, or for any other IPdevice). In this manner, multiple receiving client devices tune into ordownload the same manifest or playlist, but only act on a portion of themanifest or playlist that describes the content that is destined forthem. For example, manifest or playlist metadata can provide and includemarkers that would dynamically trigger behavior in the various receivingIP client devices that have been pre-set to look for a particularmarker. Accordingly, a first alternate content marked with a firstpre-determined marker may be intended for viewing on tablet clientdevices while a second alternate content marked with a secondpre-determined marker may be intended for viewing on smartphone clientdevices.

By creating, modifying or rebuilding the playlist or manifest originallyintended solely for adaptive streaming of the primary content alone toalso include URIs for different related alternate media content, theaffiliated auxiliary client devices are able to tune into the samecontent title being consumed by the primary video viewing device andsimultaneously use the same manifest or playlist being used by theprimary video viewing device. This enables the numerous affiliatedauxiliary client devices to readily stay in-sync with the primarycontent with respect to playing of the various related streams. Forinstance, an alternate viewing angle being displayed on an auxiliaryclient device would be synchronized in time with the primary viewingangle being displayed on the primary viewing device.

In addition, consumption of the various contents can requireauthentication and access control mechanisms to ensure that only clientdevices associated with a particular subscriber's account are beingpermitted access to the multi-stream playlist. Thus, the serviceprovider is able to retain control over which subscribers and whichsubscriber's devices the suite of content may be viewed. In the abovedescribed manner, a means to deliver coordinated content to a multitudeof pre-registered and authenticated affiliated client devices in asynchronized fashion is provided.

For purposes of example, MPEG-DASH provides a streaming technique thatcan be used in an embodiment. Other HTTP-based streaming techniques,such as HLS, SS and HDS, may also be utilized. For DASH, the actual A/Vstreams are referred to as the Media Presentation and the manifest fileis referred to as the Media Presentation Description (MPD). By way ofexample, FIG. 2 shows the structure of a MPD 30 having a MediaPresentation 32 with a collection of structured audio/video content thatincorporates “periods” 34, “adaptation sets” 36, “representations” 38,and “segments” 40.

The media presentation 32 defines the video sequence with one or moreconsecutive periods 34 that segment or chunk the video from start tofinish. Each period 34 contains multiple adaptation sets 36 that containthe content that comprises the audio/video experience. Each adaptationset 36 contains multiple representations 38, each being a single streamin the adaptive streaming experience. In FIG. 2, “Representation 1”provides 640×480 image resolution at a bit rate of 500 Kbps, and“Representation 2” provides the same image resolution, 640×480, but at alower bit rate, 250 Kbps. Each representation 38 is divided into mediasegments 40 which are chunks of data presented in discrete files (suchas Media Segment 1, Media Segment 2, Media Segment 3 . . . Media Segment20 shown in FIG. 2) or as byte ranges in a single media file.

The DASH manifest file (i.e., the Media Presentation Description) 30 isan XML file that identifies the various content components and thelocation of all alternative streams. In an embodiment, MPD syntax isused as a mechanism to describe relationships between different relatedstreams thereby enabling a set of related, but different, content to beconsumed in parallel by a registered subscriber. This enables theaffiliated client devices to identify and start playback of the initialsegments 40 simultaneously, switch between representations 38 asnecessary to adapt to changing CPU and buffer status, and changeadaptation sets 36 to respond to user input.

In the embodiments disclosed herein, the MPD is the common point ofsynchronization across the multiple client devices presenting related,synchronized and coordinated content at a subscriber location. By way ofan example, a user may be viewing a sporting event on a primary display,such as a television, while using a tablet client device as anaffiliated secondary or auxiliary display. The tablet client device mayselect to display alternate views showing instant replays, statistics,or the like. The alternate content streams can be described in the MPD30 in separate adaptation sets 36. Also, since the MPD is constructedwith respect to a common timeline, events such as advertisement breakscan be reflected in a synchronized manner on all participatingaffiliated client devices. This also enables different or coordinatedadvertisements to be simultaneously displayed on multiple participatingclient devices during such breaks.

FIG. 3 is a diagram illustrating an embodiment of components of a system50 that can build a multi-stream playlist and make primary content andrelated alternate contents available to a subscriber of a multi-streamplaylist. The multi-streaming content delivery system 50 includes amulti-stream playlist builder or rebuilder 52 receiving and building amulti-stream playlist or manifest (i.e., a MPD) from informationprovided by an Adaptive Streaming Video Source 54 (see communicationlink 56), an Advertisement Related Content Source 58 (see communicationlink 60), and an Alternate Content Coordination Manager 62 (seecommunication link 64).

The adaptive streaming video source 54 provides a source of audio andvideo content for the primary content that has been transcoded,encrypted and packaged. Thus, the adaptive streaming video source 54provides a playlist, manifest or MPD created for the primary content tothe rebuilder 52. In addition, the adaptive streaming video source 54may also provide the playlist or manifest and the adaptive bit streammedia files to a streaming server 66 via a communication link 68. Inthis manner, subscribers not registered for the multi-streaming serviceare still able to receive adaptive streaming of the primary content byitself without the ability to obtain the alternate content.

The advertisement related content source 58 (i.e., the SCTE-130 Admanagement subsystem) provides the rebuilder 52 with URIs foradvertisement related content for being spliced into the playlist forthe primary content.

The alternate content coordination manager 62 provides addressinginformation, markers, triggers, keys or filters for each of thedifferent alternate contents and URIs for the segments or media files ofthe alternate contents to the rebuilder 52. The alternate contentcoordination manager 62 may receive input from a program schedulinginformation unit 94 so that the alternate content coordination manager62 is given access and information to program scheduling information. Inthis manner, the alternate content coordination manager 62 can determinethe types of alternate content that may be appropriate at any giventime. In addition, the alternate content coordination manager 62 may beconfigured to act off of SCTE-35 ad avail markers that exist in thevideo transport stream or may similarly react to a related identifierthat might be inserted into the stream by the SCTE-130 Ad managementsubsystem 54. Thus, a communication link 96 enables communicationsbetween the alternate content coordination manager 62 and the SCT-130 Admanagement subsystem 54.

More specifically, the alternate content coordination manager 62function can be tightly integrated with the Ad management subsystem 58via link 96 so that alternate content markers can be inserted into thevideo transport stream in a similar manner with respect toadvertisements spliced into the playlist for the primary content. Insuch a system, video streams include SCTE-35 ad placement markers, alsoreferred to as ad avails, and transcoders can be configured to detectthese markers. In traditional video systems, these markers indicatewhere ads can be spliced into the stream. In an ABR system functioningaccording to SCTE-130, the transcoder communicates these markers to thead management subsystem (in SCTE-130 terms, a Placement OpportunityInformation Service (POIS)). The POIS responds with an identifier thatthe transcoder inserts into the stream, and the identifier is ultimatelycommunicated back into the ad management subsystem downstream by aplaylist re-builder and/or by the end client. When communicated back tothe ad subsystem, the ad subsystem recognizes the identifier,communicates with other internal functions such as a campaign manager,and may also use additional information it may receive from the playlistre-builder (e.g., ad zone for the client) and will respond with theappropriate ad information that the playlist re-builder folds into theplaylist (i.e., manifest).

Accordingly, the Ad management subsystem 58 shown in FIG. 3 can beconfigured to include alternate content references for the ads (usingthe same paradigm as ads for the primary content). In this manner, theprimary client may cause a commercial concerning a particular make ofautomobile to be displayed on the primary display screen, and asecondary tablet device may be simultaneously directed to a URL for theweb site of an automobile dealer or manufacturer corresponding to themake of automobile shown on the primary display screen.

The rebuilder 52 takes the information provided from the adaptivestreaming video source 54, the advertisement related content source 58,and the alternate content coordination manager 62 and generates amodified playlist, also referred to as the multi-stream playlist, whichincludes the URIs needed for downloading and playing of the primarycontent with or without advertisement URIs spliced therein andaddressing, triggers and URIs for each of the alternate contents. Thesegments or media files for the alternate contents may be stored on thestreaming server 66 or may be stored and made available on other serverssuch as web servers 70, 72 and 74 shown in FIG. 3.

The modified playlist generated by the rebuilder 52 can be forwarded tothe streaming server 66 via a communication link 76 and stored and madeavailable to client devices 78 located at a subscriber site. Thestreaming server 66 can make the various playlists for all the contentsavailable over the content distribution network 80 which may be theInternet or a service provider network, such as a HFC network.

The system 50 can also include an Access Control Manager 82 and aSession Manager 84 for purposes of providing authentication and accesscontrol mechanisms to ensure that only client devices 78 associated witha particular subscriber's account are permitted access to the modifiedor multi-stream playlist from the streaming server 66. For instance, anauxiliary client device such as a tablet may need to download andactivate an application and register with the access control manager 82and/or session manager 84 before being permitted to tune into ordownload a particular modified playlist and be provided with channelguide information and the like regarding the multi-stream service.

The client device 78 may also need to be authenticated by the accesscontrol manager 82 each time the client device 78 tunes into ordownloads the modified playlist. The session manager 84 also may seek torecognize the subscriber and the type of auxiliary client device (i.e.,tablet, personal computer, smartphone, etc.). Provided the subscriberand client device are registered, recognized and authenticated toreceive the multi-stream service, the session manager 84 may provide aparticular type of auxiliary client device with a particular marker,key, trigger or filter associated with a particular alternate content.All the above communications can be accomplished over an Internetconnection such as link 86 shown in FIG. 3.

Accordingly, when a primary client device downloads the multi-streamplaylist, manifest or MPD, the primary content may be consumed on aprimary display. The other auxiliary client devices may also downloadthe multi-stream playlist to display alternate content synchronized withthe display of the primary content. Thus, as shown in FIG. 3, each ofthe affiliated client devices (primary and auxiliary) may pull or fetchthe multi-stream playlist as shown by arrows 88 in FIG. 3 over thenetwork using HTTP fetches or gets or other transfer protocol.

As discussed above, after authentication with the session manager 84,each of the auxiliary client devices 78 can tune into or download themodified playlist and use the marker, trigger, key or filter provided toit by the session manager 84 to obtain from the modified playlist theparticular URIs for the alternate media content intended for theparticular type of auxiliary client device. Thereafter, the auxiliaryclient device 78 uses these URIs to download and buffer the alternatecontent, such as from alternate content web servers 70, 72 or 74 via thecontent distribution network 80 (see arrows 90 in FIG. 3). Thus, one ofthe alternate contents can be played on each of the auxiliary clientdevices 78 in a highly coordinated and synchronized manner with theprimary content. This also includes synchronization of advertisementbreaks as discussed above. As an alternative, if a subscriber is notregistered for a particular multi-stream service, the subscriber may beable to stream the primary content in an adaptive manner as shown byarrows 92 in FIG. 3 so that the same primary content can be viewed onany of a variety of different client devices.

Accordingly, as shown in FIG. 3, the delivery system 50 can be used toprovide the primary content to any type of client device via an adaptivestreaming technique. The delivery system can also provide registrationand authentication of auxiliary client devices for receiving amulti-streaming service. If the auxiliary client device is recognized asa subscriber for the service, the auxiliary client device is able totune into or fetch the single modified playlist file that issynchronized with the primary content playing on a primary videodisplay. The auxiliary devices can fetch media files for the alternatecontent appropriate or selected for the auxiliary client device and playthe alternate content in a manner substantially synchronized andcoordinated with the playing of the primary content. Different auxiliaryclient devices and/or different types of auxiliary client devices cansubstantially simultaneously obtain the same modified playlist and usethe triggers provided by the session manager to filter out the URIs formedia files of alternate contents destined for the particular clientdevices. Thus, multiple auxiliary contents may be played in asynchronized, coordinated manner with the primary content.

With respect to synchronization, a typical manifest might represent atotal duration of about 30 seconds, e.g., three 10 second videosegments, and at any given time, a couple of manifests may exist on aweb server. For instance, in a single client scenario, the clientdownloads a manifest and that particular manifest may remain on the webserver for a finite amount of time along with one or more additionalmanifests representing the next, or next several, 30 second intervals ofvideo segments in sequence and so forth. Thus, when considering amulti-client scenario, each client device may request, fetch, download,etc. a manifest at slightly offset times and may potentially beoperating on different manifests. In addition, even if all clientdevices are working off the same manifest, there is no way to ensurethat they will be perfectly in sync such that they are all on the timeperiod associated within the same segment. For some content, such aminor offset may not pose a problem, and the client devices will besufficiently synchronized. However, for related content where tightersynchronization is required, synchronization may be improved in a mannerdiscussed below.

One approach for improving synchronization is to require the primaryclient device to periodically report its state (e.g., I'm currentlyrendering segment x) to the session manager 84, and then have thesession manager 84, in turn, communicate this state to all of thesubscriber's registered secondary client devices. As an alternateapproach, the session manager 84 can be configured to infer the state ofthe primary client device and communicate the inferred state to thesubscriber's registered secondary client devices. Yet another approachto improve synchronization is to tighten (i.e., reduce) the time periodthat a given manifest is permitted to remain available for download on aweb server.

Thus, the system 50 enables a service provider to deliver value-add,coordinated services to a multitude of affiliated subscriber devices ina coordinated fashion and enables the service provider to provide suitesof value-add content to consumers in a creative manner.

In the foregoing specification, specific embodiments of the presentinvention have been described. However, one of ordinary skill in the artappreciates that various modifications and changes can be made withoutdeparting from the scope of the present invention as set forth in theclaims below. Accordingly, the specification and figures are to beregarded in an illustrative rather than a restrictive sense, and allsuch modifications are intended to be included within the scope of thepresent invention.

In addition, the above referenced devices, servers, components, sources,equipment, boxes, tuners, units and the like for carrying out the abovemethods can physically be provided on a circuit board or within anotherelectronic device and can include various processors, microprocessors,controllers, chips, disk drives, and the like. It will be apparent toone of ordinary skill in the art that the processors, controllers,tuners, units, managers, rebuilders, and the like may be implemented aselectronic components, software, hardware or a combination of hardwareand software.

One of ordinary skill in the art appreciates that various modificationsand changes can be made without departing from the scope of theseembodiments as defined in the appended claims.

We claim:
 1. A method of streaming multimedia content data over anetwork, comprising the steps of: building a manifest including a listof Universal Resource Indicators (URIs) for different segments ofmultimedia content data for selected primary multimedia content and alist of URIs for different segments of multimedia content data for atleast one alternate multimedia content related to and different from theselected primary multimedia content; and making the manifest availablefor download by primary and alternate client devices over the networkwith a transfer protocol.
 2. A method according to claim 1, wherein thetransfer protocol is Hyper-Text Transfer Protocol (HTTP)-basedstreaming.
 3. A method according to claim 1, wherein the transferprotocol is Dynamic Adaptive Streaming over HTTP (MPEG DASH), whereinthe manifest is a Media Presentation Description (MPD), and wherein thelist of URIs for different segments of multimedia content data for theselected primary multimedia content and the list of URIs for differentsegments of multimedia content data for the at least one alternatecontent are provided in separate adaptation sets within the MPD.
 4. Amethod according to claim 1, further comprising the step of transmittingthe manifest to a subscriber site so that the at least one alternatecontent is available to an auxiliary client device affiliated with theprimary client device in a manner synchronized with the selected primarymultimedia content.
 5. A method according to claim 1, further comprisingthe step of marking the list of URIs for the different segments ofmultimedia content data for the at least one alternate content with amarker able to trigger an auxiliary client device affiliated with theprimary client device to obtain and play the at least one alternatecontent.
 6. A method according to claim 5, further comprising the stepsof authenticating the auxiliary client device and transmittinginformation of the marker to the auxiliary client device after saidauthenticating step.
 7. A method according to claim 1, wherein saidbuilding step includes modifying an initial manifest generated for theselected primary multimedia content by splicing the list of URIs fordifferent segments of multimedia content data for the at least onealternate content into the initial manifest to produce a modifiedmanifest for multi-streaming the selected primary multimedia content andthe at least one alternate content in a synchronized manner.
 8. A methodof streaming multimedia content data over a network to affiliated clientdevices, comprising the step of: downloading a manifest with a primaryclient device over the network with a transfer protocol, the manifestincluding a list of Universal Resource Indicators (URIs) for differentsegments of multimedia content data for a selected primary multimediacontent and a list of URIs for different segments of multimedia contentdata for at least one alternate content related to and different fromthe selected primary multimedia content.
 9. A method according to claim8, further comprising the step of: downloading the manifest with atleast one auxiliary client device affiliated with the primary clientdevice over the network with a transfer protocol to enablesynchronization of display of the selected primary multimedia content ona primary display controlled by the primary client device and display ofthe at least one alternate content on the at least one auxiliary clientdevice.
 10. A method according to claim 9, wherein the transfer protocolis Hyper-Text Transfer Protocol (HTTP)-based streaming.
 11. A methodaccording to claim 9, wherein the transfer protocol is Dynamic AdaptiveStreaming over HTTP (MPEG DASH), wherein the manifest is a MediaPresentation Description (MPD), and wherein the list of URIs fordifferent segments of multimedia content data for the selected primarymultimedia content and the list of URIs for different segments ofmultimedia content data for the at least one alternate content areprovided in separate adaptation sets within the MPD.
 12. A methodaccording to claim 9, further comprising the step of obtaining a markerfor the at least one auxiliary client device to trigger the at least oneauxiliary client device to obtain the different segments of multimediacontent data for at least one alternate content for display.
 13. Amethod according to claim 12, wherein the type of device of the at leastone auxiliary client device is selected from the group selected from atablet, a personal computer, a laptop computer, a smartphone, an e-bookreader, and a portable electronic device having an associated displayscreen, and wherein a different marker is used for each different typeof device.
 14. A system for streaming multimedia content data over anetwork to affiliated client devices, comprising: a multi-streamplaylist rebuilder configured to receive a manifest including a list ofUniversal Resource Indicators (URIs) for different segments ofmultimedia content data for a selected primary multimedia presentation;and an alternate content coordination manager configured to provide saidmulti-stream playlist rebuilder with a list of URIs for differentsegments of multimedia content data for at least one alternatemultimedia content that is related to and different from the selectedprimary multimedia presentation; said multi-stream playlist rebuilderbeing configured to generate a modified manifest including the list ofURIs for the different segments of the multimedia content data for theselected primary multimedia presentation and a list of URIs for thedifferent segments of the multimedia content data for the at least onealternate multimedia content.
 15. A system according to claim 14,wherein the transfer protocol is Dynamic Adaptive Streaming over HTTP(MPEG DASH), and wherein the manifest is a Media PresentationDescription (MPD).
 16. A system according to claim 15, wherein the listof URIs for the different segments of the multimedia content data forthe selected primary multimedia presentation and the list of URIs forthe different segments of the multimedia content data for the at leastone alternate content are provided in separate adaptation sets withinthe MPD.
 17. A system according to claim 14, further comprising asession manager that is configured to authenticate affiliated clientdevices registered to obtain the modified manifest and that isconfigured to transmit at least one marker to the affiliated clientdevices.
 18. A system according to claim 17, wherein said at least onemarker triggers the affiliated client devices to obtain and play aselected one of the at least one alternate multimedia content.
 19. Asystem according to claim 18, wherein the affiliated client devices areselected from a group consisting of a set-top box, a tablet, a personalcomputer, a laptop computer, a smartphone, an e-book reader, and aportable electronic device having an associated display screen, andwherein a different marker is used for each different type of device.20. A system according to claim 14, further comprising at least oneserver on which the modified manifest, the different segments of themultimedia content data for the selected primary multimediapresentation, and the different segments of the multimedia content datafor the at least one alternate multimedia content is stored and madeavailable to the affiliated client devices via a content distributionnetwork.